Drug packaging devices that automatically dispense a plurality of units of a drug (the units hereinafter meaning tablets, capsules, pills, lozenges, and any other discrete forms of a drug that can be individually handled, and the units of a drug hereinafter being referred to as simply drug units) as prescribed for a variety of illnesses and package the drug units in single doses have recently become widely available. A drug packaging device dispenses a drug, unit by unit, from a plurality of drug storage tanks to drug packaging members and packages the drug units with the drug packaging members.
To dispense a plurality of drug units from a drug storage tank, a method of vibrating the drug storage tank is generally used. In the case of the vibration dispensing, the magnitude of vibration needs to be adjusted in accordance with the size or shape of drug units. That is, when drug units in a storage tank are excessively heavy, it is difficult to dispense the drug, unit by unit. Meanwhile, when drug units are excessively light, there is a problem that a plurality of drug units is collectively moved at the same time. That is, erroneous dispensing occurs.
Therefore, research has been continuously conducted to accurately dispense a plurality of drug units, unit by unit, from a drug storage tank to a drug packaging member.